Incarcerated women are a vulnerable population with high rates (~50%) of co-occurring mental health and substance use disorders (COD). Previous research, including ours, has established that re-entry into the community from prison is characterized by scarcity, competing demands, and tradeoffs, especially for women with COD. Faced with poverty, mental illness, addiction, poor physical health, poor vocational skills, lack o education, and violence in their environments, re-entering women with COD need to find and maintain safe, substance-free housing, transportation, legal employment, and mental health and substance use treatment. They must do all of this while avoiding mental health and substance use relapse and furthering efforts to re- unite with children. They are often faced with large and consequential trade-offs: meeting a need in one area may dramatically compromise another. Behavioral economics and cognitive psychology studies of similar circumstances (scarcity, trade-offs, repeated challenges to self-control) in the laboratory suggest that these circumstances consume cognitive processing resources, produce (reversible) decrements in fluid intelligence and ability to inhibit impulses, rendering subsequent decisions prone to favoring impulsive, intuitive, and often regrettable options. If these effects hold true for women leaving prison, the implication would be that the failure to devote adequate resources to discharge planning and re-entry services may contribute to some women having not only practical challenges, but being cognitively impaired, with little cognitive capacity to devote to finding treatment or remembering medications, and able to do little besides the familiar behaviors that compromise their mental and physical health. The purpose of this study is to examine how the re-entry context affects the cognitive processing and subsequent health decisions of 104 women with COD. Dependent variables include fluid intelligence and cognitive control (an RDoC construct), ability to locate and persist in post-release mental health and substance use treatment, and craving for and ability to resist substance use and risky sex. We also hypothesize that impaired cognitive functioning will mediate the effects of inadequate re-entry services on post-release psychiatric distress, substance use relapse, risky sex, receipt of treatment, medication adherence, and functioning. This R21 proof-of-concept study will provide actionable knowledge by extending laboratory findings to a high-risk clinical population, examining a novel, important mechanism (i.e., contextually-driven decrements in cognitive functioning) by which known prison re-entry health failures occur and opening new avenues for intervention. Characteristics of re-entering prisoners that profoundly affect health behaviors (fluid intelligence, self-control, persistence) previously thought to be static individual differene variables may be influenced by contextual factors and thus more open to remedies than previously believed.